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United States Patent |
5,791,812
|
Ivey
|
August 11, 1998
|
Collision performance side impact (automobile penetration guard)
Abstract
Apparatus and methods are described for preventing the penetration of
vehicles by narrow objects such as guardrail ends or portions of a
guardrail end treatment during a collision. In one embodiment, portions of
an ET-2000 guardrail extruder terminal are adapted for improved operation
during impacts by attachment of a penetration guard. The penetration guard
may also be affixed to other guardrail end treatments or even other
suitable highway objects to create an improved safety apparatus. The
penetration guard includes a frame and is affixed to the impact head of an
ET-2000 guardrail extruder terminal. The frame is greatly collapsible when
impacted from a substantially end-on direction. However, when impacted
from a direction other than substantially end-on, the frame is
substantially non-collapsible and maintains its integrity. The frame
includes an outer housing which defines a central opening. The housing is
preferably formed of a unitary outer of sheet metal which surrounds the
central opening. In alternative embodiments, the housing is made up of a
number of hingedly affixed plates or panels or deformable members which
collectively change shape in a predetermined manner. In some embodiments,
the frame includes an interior brace which helps prevent collapse of the
frame when the frame is impacted from its side. If desired, the central
opening may be filled with an appropriate energy absorbing deformable
filler material.
Inventors:
|
Ivey; Don L. (Bryan, TX)
|
Assignee:
|
The Texas A&M University System (College Station, TX)
|
Appl. No.:
|
729182 |
Filed:
|
October 11, 1996 |
Current U.S. Class: |
404/6; 256/13.1; 404/9; 404/10 |
Intern'l Class: |
E01F 013/00; E01F 015/00; E01F 009/00 |
Field of Search: |
404/6,9,10
256/1,13.1
|
References Cited
U.S. Patent Documents
2154818 | Apr., 1939 | Mayer | 256/13.
|
2776116 | Jan., 1957 | Brickman | 256/13.
|
3643924 | Feb., 1972 | Fitch | 256/13.
|
3661359 | May., 1972 | Walker | 256/1.
|
3690619 | Sep., 1972 | Kendall | 256/13.
|
4655434 | Apr., 1987 | Bronstad | 256/13.
|
4674911 | Jun., 1987 | Gertz | 404/6.
|
4678166 | Jul., 1987 | Bronstad et al. | 256/13.
|
4815565 | Mar., 1989 | Sicking et al. | 188/32.
|
4928928 | May., 1990 | Buth et al. | 256/13.
|
5022782 | Jun., 1991 | Gertz et al. | 404/6.
|
5078366 | Jan., 1992 | Sicking et al. | 256/13.
|
5112028 | May., 1992 | Laturner | 256/13.
|
5391016 | Feb., 1995 | Ivey et al. | 404/6.
|
5407298 | Apr., 1995 | Sicking et al. | 404/6.
|
5490661 | Feb., 1996 | Stevens et al. | 256/13.
|
Foreign Patent Documents |
094846 | Nov., 1983 | EP.
| |
2651811 | May., 1969 | FR.
| |
1295582 | Mar., 1991 | DE.
| |
Other References
An End Treratment for Concrete Barriers Used in Work Zones; Texas
Transportation Institute State Department of Highways and PUblic
Transportation; Research Report 262-2; Aug. 1982 (Rev. 02-83) (19 pp.).
A Guide to Standardized Highway Barrier Hardware; AASHTO-AGC-ARTBA Joint
Committee; Subcommittee on New Highway Materials, Tash Force 13 Report;
(undated) (17p.).
Colorado Median Barrier End Treatment Tests; R. G. Robertson and H. E.
Ross, Jr.; May 1981; (15 pp.).
|
Primary Examiner: Graysay; Tamara L.
Assistant Examiner: Hartmann; Gary S.
Attorney, Agent or Firm: Conley, Rose & Tayon, P.C.
Claims
What is claimed is:
1. A penetration guard for attachment to a guardrail end treatment to
substantially reduce and spread initial impact load, the penetration guard
comprising:
a cushioning frame adapted to be affixed to a guardrail end treatment, the
frame having an outer housing defining a central opening;
the frame being greatly collapsible from a substantially end-on impact and
being substantially non-collapsible during a non-end-on impact.
2. The penetration guard of claim 1 wherein the cushioning frame comprises
a sheet metal shell and a supporting lateral brace piece located within
the central opening.
3. The penetration guard of claim 1 further comprising means for attachment
of the frame to a guardrail end treatment.
4. The penetration guard of claim 2 wherein the frame comprises a unitary
section of sheet metal.
5. The penetration guard of claim 4 wherein portions of the sheet metal
extend downwardly.
6. The penetration guard of claim 1 wherein the frame collapses during a
vehicular impact to present an end-on impact area of expanded width, the
width of said impact area being approximately four feet.
7. The penetration guard of claim 1 wherein the frame comprises a plurality
of hinged plates.
8. The penetration guard of claim 1 wherein the frame comprises a plurality
of corrugated panels.
9. The penetration guard of claim 8 further comprising a cross-brace.
10. The penetration guard of claim 1 further comprises a collapsible filler
disposed within said central opening.
11. A safety apparatus for attachment to an end of a highway guardrail, the
apparatus comprising:
a. a guardrail end treatment for reducing danger associated with an end-on
impact with a guardrail; and
b. a penetration guard for preventing penetration of portions of a vehicle
by the guardrail end treatment.
12. The safety apparatus of claim 11 wherein the guardrail end treatment
comprises a guardrail extruder terminal.
13. The safety apparatus of claim 11 wherein the guardrail end treatment
comprises a breakaway cable terminal.
14. The safety apparatus of claim 11 wherein the guardrail end treatment
comprises a modified eccentric loader terminal.
15. The safety apparatus of claim 11 wherein the guardrail end treatment
comprises a slotted rail terminal.
16. The safety apparatus of claim 11 wherein the penetration guard
comprises a cushioning frame affixed to a portion of the guardrail end
treatment, the frame having an outer housing defining a central opening.
17. The safety apparatus of claim 12 wherein the penetration guard
comprises a supporting lateral brace located within the central opening.
18. A guardrail assembly for placement alongside a roadway, the guardrail
assembly comprising:
a. a guardrail;
b. a guardrail end treatment incorporated into one end of the guardrail for
reducing the effects of vehicular impacts with the end of the guardrail;
and
c. a penetration guard for preventing penetration of portions of a vehicle
by the guardrail end treatment.
19. The guardrail assembly of claim 18 wherein the guardrail end treatment
comprises a guardrail extruder terminal.
20. The guardrail assembly of claim 18 wherein the penetration guard
comprises a collapsible metal frame.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for improved safety
for end treatments on roadway guardrails and other appurtenances. In one
particular aspect, the present invention features a modification of the
ET-2000 safety device.
2. Description Of Related Art
Guardrails present a unique fixed object safety problem due to the raised
ends which they sometimes present. Therefore, a number of guardrail end
treatments have been developed which attempt to reduce the hazard
presented by the raised ends. Guardrail end treatments seek to reduce the
harmful effects of collisions with the ends of guardrails by absorbing,
redirecting or cushioning impacts with the end of the rail. One such end
treatment is the Slotted Rail Terminal (SRT) which is described in U.S.
Pat. No. 5,407,298 by Sicking et al. and assigned to the assignee of the
present invention. That patent is incorporated herein by reference.
Another example is the Eccentric Loader Guardrail Terminal or Modified
Eccentric Loader Terminal (MELT) described, for example, in U.S. Pat. No.
4,678,166, issued to Bronstad et al. also incorporated herein by
reference.
The Breakaway Cable Terminal (BCT) end treatment is one of the most widely
used guardrail end treatments in the United States. It has been a well
known end treatment for many years. Another guardrail end treatment, known
commercially as ET-2000 or as the Guardrail Extruder Terminal, has been in
use for several years as an end treatment for the end of a W-shaped beam
member guardrail. The ET-2000 serves to attenuate impacts with the end of
the guardrail and provides anchorage for impacts to the sides of the
guardrail. In an end-on impact, the ET-2000 progressively flattens the
beam of the guardrail and bends the flattened member in a curvilinear arc
in a direction away from the colliding vehicle. Aspects of the ET-2000
have been described and claimed in U.S. Pat. No. 4,928,928, entitled
"Guardrail Extruder Terminal," issued to Buth et al. on May 29, 1990, and
U.S. Pat. No. 5,078,366, entitled "Guardrail Extruder Terminal," issued to
Sicking et al. on Jan. 7, 1992. Both of these patents have been assigned
to the assignee of the present invention and are incorporated herein by
reference. The ET-2000 and the SRT are available commercially from Trinity
Industries in Dallas, Texas.
It has been noted that the ET-2000, as well as all other end treatments
known to the inventor, have the potential to puncture the passenger
compartment a colliding vehicle if the vehicle is turned sideways prior to
impacting the end of a guardrail. As a vehicle is stopped, the vehicle
structure must overcome the inertia of the ET-2000 head and the force
needed to begin flattening and bending the W-beam rail. If the vehicle
impacts the ET-2000 head with its front, the portions of the vehicle can
deform for approximately two feet before the passenger compartment will be
punctured by the ET-2000 head or elements within the front compartment,
such as the engine, which are pushed toward the passenger compartment by
the ET-2000 head.
The passenger doors, however, present a point of vulnerability for vehicle
passengers. The front passenger doors are located between the "A" and "B"
door pillars which frame the vehicle doorways. The location and
arrangement of these pillars will be shown and described shortly with
reference to FIGS. 13 and 14. These pillars are relatively strong
structurally supporting members of the vehicle's roof. The "A" pillar, for
instance, on the driver's side of the vehicle is located at the left front
corner of the passenger compartment along the forward edge of the doorway
and generally runs from the vehicle roof to its floor frame. The "B"
pillar on the driver's side of the vehicle is located toward the left rear
corner of the front passenger compartment and also generally runs from the
vehicle roof to the floor frame. The space between the "A" and "B" pillars
on a vehicle is typically 40-50 inches.
When a vehicle impacts an ET-2000 device, or other guardrail end treatment,
such as an SRT, MELT or BCT, the impact head of the end treatment may
generally fit easily within the gap between the "A" and "B" pillars,
thereby often permitting penetration of the passenger compartment of the
vehicle by the impact head. Simply padding the impact head will not
prevent penetration of the compartment. Making an extremely wide head is
generally impractical and might serve to block vision or distract drivers.
Generic crash cushions have been developed in the prior art. One example is
that described in U.S. Pat. No. 3,643,924, "Highway Safety Device" issued
to Fitch. Devices such as this do serve the purpose of attenuating impact
during a vehicle collision primarily by the "conservation of momentum"
principle which is why they are filled to varying degrees with sand. Such
a device is simply a guardrail wrapped around sand-filled cylinders. This
arrangement was not designed to prevent injury in side impact collisions,
nor is it designed to be affixed to an object such as a guardrail end or
an ET-2000 device.
SUMMARY OF THE INVENTION
The present invention offers methods and apparatus for preventing
penetration of vehicles by narrow objects such as guardrail ends or
portions of a guardrail end treatment during a collision. The present
invention has particular application to fixed objects which tend to
present an impaling hazard to vehicles, such as guardrails and some
highway median barriers. In one preferred embodiment of the invention, an
ET-2000 guardrail end treatment is adapted for improved operation during
impacts by attachment of a Collision Performance Side Impact (CPSI)
automobile penetration guard. The apparatus may also be affixed to other
guardrail end treatments or other suitable items which might be impacted
during a highway collision in order to improve their safety by reducing
the initial velocity changes and lowering the peak impact forces that
result in penetration of the vehicle and violation of the passenger
compartment.
In one exemplary embodiment, the invention features a penetration guard
which comprises a frame which is affixed to the impact head of an ET-2000
guardrail extruder terminal or other roadway object. The frame is designed
to be greatly collapsible when impacted from a substantially end-on
direction. However, when impacted from a direction other than
substantially end-on, such as a glancing impact direction, the frame is
substantially non-collapsible and maintains its integrity. The frame
includes an outer housing which defines a central opening. In one
embodiment, the housing is formed of a unitary outer of sheet metal which
surrounds the central opening. In alternative embodiments for the
penetration guard, the housing is made up of a number of hingedly affixed
plates or corrugated panels or deformable members which collectively
change shape in a predetermined manner. In some embodiments, the frame
includes an interior brace which helps prevent collapse of the frame when
the frame is impacted from its side. If desired, the central opening may
be filled with an appropriate energy-absorbing or deformable filler
material. A penetration guard is also combinable with alternative
guardrail end treatments, such as the BCT, SRT and MELT to create improved
safety apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an exemplary guardrail end equipped with an
ET-2000 device which incorporates a penetration guard constructed in
accordance with a preferred embodiment of the invention.
FIG. 2 is a side view of the guardrail end of FIG. 1.
FIG. 3 and 4 are closer views of the penetration guard of FIGS. 1 and 2,
FIG. 4 being a partial cutaway
FIG. 5 is an exploded view of the penetration guard shown in FIGS. 3 and 4.
FIG. 6 is a side view of an alternative embodiment of a penetration guard
incorporating substantially flat panels of plate or plate sections.
FIG. 7 is an isometric view of the penetration guard of FIG. 6.
FIG. 8 is a side view of a third embodiment of the penetration guard
incorporating reinforced panels.
FIG. 9 is an isometric view of the penetration guard of FIG. 8.
FIG. 10 is a plan view of the penetration guard of FIGS. 1 and 4 after
impact with a vehicle.
FIG. 11 is a plan view of the penetration guard of FIGS. 8-9 after impact.
FIG. 12 is a plan view of the penetration guard of FIGS. 6-7 after impact.
FIG. 13A is a plan view of a prior art modified eccentric loader terminal
melt end treatment.
FIG. 13B depicts a melt end treatment which has been modified in accordance
with the present invention to incorporate an exemplary penetration guard.
FIG. 14A is a plan view of a prior art BCT end treatment.
FIG. 14B is a plan view of a BCT end treatment having been modified to
incorporate an exemplary penetration guard.
FIG. 14C is an isometric, exploded view of the modified BCT end treatment
in FIG. 14B.
FIG. 15 is a plan view of an exemplary safety apparatus constructed in
accordance with the present invention immediately prior to an end-on
impact with the side of an approaching automobile.
FIG. 16 is a plan view of the exemplary safety apparatus shown in FIG. 15
during the initial stages of impact with the automobile.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The methods and apparatus of the present invention have been developed for
and are primarily directed toward use with ET-2000 type guardrail end
treatments. However, the invention has application to numerous other
guardrail end treatments and other roadway objects which present similar
hazards to motorists.
In accordance with the present invention, exemplary CPSI penetration guard
arrangements are described in which a frame is provided which spreads the
impact load over a much larger area of the structure of an impacting
vehicle. The combination of the penetration guard and the guardrail end
treatment results in a more effective safety apparatus. The frame
collapses over a short distance in a relatively controlled manner at a low
collapse load and over an expanded area, preventing penetration of the
door. The disadvantage of a wider end being more susceptible to vehicle
glancing impacts is more than countered by the increased visibility of the
wider end and the damage reduction from glancing impacts due to the
lateral stability of CPSI.
Also, the progressively rising load due to the controlled structural
deformation of the frame also acts to accelerate a guardrail head or end
over a much larger period of time, thus significantly reducing the inertia
load on the vehicle caused by the rail end. In the described embodiments,
the frame of the penetration guard is adapted to readily collapse in an
end-on impact while substantially maintaining its structural integrity
during an impact along the side of the frame.
Referring first to FIGS. 1 and 2, a preferred exemplary penetration guard
10 is shown affixed to an ET-2000 device 12 which has been installed onto
a guardrail installation 13 along a roadway (not shown). The guardrail 13
includes a horizontal rail 15 mounted upon one or more support posts 17.
The ET-2000 device 12 includes a feeder chute 19 and a front striking
plate 21. Referring now as well to FIGS. 3-5, the penetration guard 10
includes a collapsible frame 14 which includes a unitary sheet metal shell
16. The sheet metal is preferably of #10 gage material, however, other
suitable thicknesses or gages may be used. The sheet metal shell 16 is
bent or formed to surround a central opening 18. The shell 16 is then
affixed to the impact head of an ET-2000 12 by means of suitable
connectors 20. It is presently preferred that the connectors 20 comprise a
headless, or round-head, bolt and nut arrangement as the headless nature
of the round head bolt presents a smooth appearance and reduces the number
of sharp edges or protrusions. It is also preferred that the shell 16 be
formed so that at least a portion 17 extends downwardly toward the ground
22.
The frame 14 also includes a brace piece 24. The brace piece 24 is
preferably formed of 1/4" steel plate or plate sections, but other
suitable plate thicknesses and materials may be used. The brace piece 24
is generally fashioned to be sturdier than the shell 16, which is made of
sheet metal. The brace piece 24 is made up of a central attachment section
26 through which connectors 28 are disposed to affix the brace piece 24 to
the ET-2000 device 12. Two wing braces 30 extend laterally from the
central attachment section 26 and are affixed at their opposite ends to
portions of the sheet metal shell 16. The brace piece 24 provides some
support to the frame 14 against premature collapse and, because the frame
14 is sturdier than the shell 16, it provides lateral support if the frame
14 is impacted upon its longitudinal side as would occur if there is a
grazing or glancing impact of the terminal by a vehicle. This would occur
when a vehicle approaches the frame 14 substantially from a direction such
as that illustrated by the arrow labeled "Glancing Impact" in FIG. 1.
However, if the frame 14 is impacted substantially from the end, as
indicated by the FIG. 1 arrow labeled "End Impact," the frame 14 should
readily collapse in a manner which will be described.
Upon an end impact, the penetration guard 10 will deform so as to expand
laterally outward forming a wide barrier to penetration of the doorway by
the object, as depicted in FIG. 10. Prior to impact, the penetration guard
10 presents an end-on impact area of reduced width or "w" in FIG. 1. A
preferred range of reduced widths "w" is generally from approximately 2
feet to approximately 4 feet. A particularly preferred reduced width "w"
is approximately 2 1/2 feet. During an end-on collision, the frame 14 of
the penetration guard deforms so that a second end-on impact area of
greater width, "w" in FIG. 10, is provided. The width of the second
expanded impact area, "w" approaches and may exceed the width of space
between the "A" and "B" door pillars for a vehicle. Preferably, the width
of the second expanded area is about four feet.
If desired, the central opening 18 may be filled with a readily deformable,
energy-absorbent material or member such as aluminum cans 32, partially
shown in FIG. 3. Alternative filler materials or members include styrofoam
peanuts and ultra low strength concrete.
A second embodiment of the penetration guard of the present invention is
depicted in FIGS. 6-7 and 12. In this embodiment, the penetration guard 50
is similarly affixed to the impact head of an ET-2000 device 52. The frame
54 of the penetration guard 50 is constructed of a number of plates or
plate sections 56, 58, 60, 62, 64, 66 and 68. These plates or plate
sections are less than 1/2" in thickness. A preferred range of thickness
is 1/8"-1/4". The plates surround a central opening 63. The plates are
hinged with a suitably sized pin or connector, such as a 3/4" pin 72, at
the upstream end of the frame 54 to assist inward collapse of the frame 54
in an end-on impact. The construction of welds and an upstream pivot point
permits the frame 54 to retain structural integrity during an impact from
the side of the frame while readily collapsing during an end-on impact.
FIG. 12 shows the penetration guard 50 after an end-on impact with a
vehicle (not shown). As with the first embodiment, the frame 54 deforms so
that a second end-on impact area of greater width is provided.
A low-density crushable concrete insert (not shown) may be used as a filler
as well. Low-density crushable concrete members are described in U.S. Pat.
No. 4,909,661 issued to Ivey which is assigned to the assignee of the
present invention and incorporated herein by reference. The crushable
concrete insert would be cast in or cut to a suitable shape to fit within
the central opening 68. Use of a crushable concrete insert as filler is
recommended primarily for use with the second embodiment of CPSI
penetration guard which is described and shown in FIGS. 6, 7 and 12. It is
noted that, in most instances, use of such filler will not be necessary.
A third embodiment of the penetration guard of the present invention is
shown in FIGS. 8-9 and 11. Penetration guard 80 is affixed to the impact
head of an ET-2000 device 82. The frame 84 of the penetration guard 80 is
fashioned from a plurality of reinforced metal panels 86, 88, 90, 92, 94
and 96 which are affixed to one another by welding. The panels 88, 90, 92,
94, 96 may be either flat or corrugated. In this embodiment depicted in
FIGS. 8-9 and 11, these panels are flat metal panels of the same thickness
as that of the plates 56, 58, 60, 62, 64, 66 and 68. The frame 84 also
includes a plate 98 by which the frame 84 is affixed to the impact head
82. At the upstream end of the frame 84 is a vertical pipe segment 102.
The pipe segment 102 provides vertical stiffness to the frame 84 and
extends low enough toward the ground to be able to engage low frame
members of impacting vehicles. Horizontal pipe segments 104 are welded to
the panels 86, 88, 90, 92, 94 and 96 to provide additional strength to the
frame 84. Also, cross bracing 106 is provided within the opening 108
defined by the frame 84. Preferably, the cross-bracing 106 is made of
steel pipe. Preferably also, the cross-bracing 106 is not fixedly attached
to portions of the frame 84. Instead, the bracing 106 should be supported
upon corrugations in the panels or upon the pipe segments 104 or otherwise
placed so that it will lend strength to the frame 84 during an impact from
the side. An alternative method for placement of the cross-bracing within
the opening 108 would be to dispose the ends of the pipe segments onto
short cylindrical metal rod segments which are welded at their other ends
to the frame 84. The cylindrical metal rod segments would have a diameter
less than the interior diameter of the pipe segment so that the rod
segment could be easily inserted into the pipe segment. In an end-on
impact, however, the bracing 106 will fall from the frame 84 as the width
of the frame expands (see FIG. 11).
Also shown in FIGS. 8 and 9 is a preferred crushable energy-absorbing
insert 108. A 4" diameter crushable tubular member such as the Extren
Series 500 fiberglass reinforcing plastic structural shape available from
Imco Reinforced Plastics, Inc., P.O. Box 534, 858 N. Lenola Road,
Moorestown, N.J. 08057. Such members are disposed longitudinally or
parallel to the guardrail upon which the ET-2000 device 82 is mounted. The
insert 108 is preferably placed in between the cross-bracing member 106
(as shown) or above or below the cross-bracing members 106. Use of a
crushable tubular member of this nature as filler is recommended primarily
for use with the third embodiment of CPSI penetration guard which is
described and shown in FIGS. 8, 9 and 11.
Referring now to FIGS. 13A and 13B as well as 14A, 14B and 14C, alternative
embodiments are depicted in which a CPSI penetration guard is affixed to
alternative guardrail end treatments. FIG. 13A is a plan view depicting a
MELT or eccentric loader terminal 110 of the prior art which is
constructed at the end of a conventional W-beam guardrail 112. As noted
earlier, structure and operation of guardrail end treatments such as this
is described in greater detail in, for example, U.S. Pat. No. 4,678,166
issued to Bronstad et al. The guardrails 112 are provided with a plurality
of vertical supports 114 of any suitable number for vertically supporting
the W-beam guardrail 112. An eccentric lever, generally indicated by the
reference numeral 116, is provided at the upstream end. The eccentric
lever 116 includes a plurality of metal beams such as H-beams 118, which
are secured to a beam box 120, such as by welding, which is, in turn,
connected to an angle iron 122 which is bolted to the furthest upstream
support post 114. Enclosing the beams 118, the top of the support 114 and
the end of the W-beam rail 112 is a tubular member 124, such as a
corrugated portion of a metal culvert. The tubular member 124 is supported
by being bolted to the support 114. A conventional anchor cable 126 is
provided connected to the furthest upstream post 114 and to a connection
128 to provide tensile forces to redirect impacting vehicles downstream
from the upstream end. A strut 130 is provided between the steel tube
foundations (not shown) of posts 114 so that the strut 130 acts along with
cable 126 to resist cable loads caused by impacts downstream of the
attachment 128. The tubular member 124 is generally intended to prevent
snagging of an impacting vehicle with beams 118 and, to a limited degree,
serve as a barrier for the end of the rail 112. However, the tubular
member 124 may be insufficient as a barrier and, thus, permit penetration
of the passenger compartment by portions of the beams 118 in a side
impact.
FIG. 13B depicts the eccentric loader terminal arrangement 110 after having
been modified in accordance with the invention to incorporate a CPSI
penetration guard 132. The tubular member 124 has been removed and a
penetration guard assembly 132 has been attached to one or more of the
beams 118 by bolting, welding or similar means. The penetration guard
assembly 132 shown is of the type depicted in FIGS. 1-5. However,
alternative designs may be used as well.
FIG. 14A depicts a plan view of one end of an exemplary guardrail assembly
end 134 which incorporates a conventional BCT end treatment. Although such
end treatments are well known in the art, it is pointed out that further
details regarding their construction are available from publications such
as "A Guide to Standardized Highway Barrier Hardware," Task Force 13
Report, AASHTO-ABC-ARATBA Joint Committee, Subcommittee on New Highway
Material. The guardrail assembly end 134 includes a corrugated rail 136
such as a W-section rail which is supported by a number of support posts
of which only the furthest upstream is depicted at 138. The W-section rail
136 is affixed by means of splice bolts 140 to a curved end member 142
which features a central flattened curved section 144 and a pair of
straightened corrugated end sections 146, 148. The corrugated end section
148 is affixed by one or more bolts 150 to the W-section rail 136.
In order to modify the BCT end 134 for attachment of a CPSI penetration
guard, bolts 150 and 149 are removed so that the curved end section 142
may be removed from the end 134. Portions of the W-section rail 136 which
then extend upstream past the end of support member 138 must then be cut
or sectioned away. The point of sectioning is indicated at line 152.
Preferably, a rectangular hollow steel tube 152 is then affixed by two
1/2" diameter bolts 156 of suitable length disposed through the upper end
of support post 138 and tube 152. It will be necessary to first detach the
corrugated member 136 from support 138 in order to add the tube 152. This
is done by removal of bolt-and-nut arrangement 157 visible in FIG. 15C.
The corrugated member 136 is then reattached. A CPSI penetration guard 154
may then be affixed to the support member and steel tube 152 by means of
bolts 156. The top bolt is preferably disposed approximately 3" from the
top of the cap 152. The bottom bolt is disposed approximately 3" from the
bottom of the cap 152. The penetration guard 154 includes a shell section
153 and a brace 155.
A method of attachment identical or similar to that described with respect
to FIGS. 14A-14C would be appropriate for affixing a CPSI penetration
guard to an SRT end treatment as well.
Now referring to FIGS. 15 and 16, operation of apparatus of the present
invention is further illustrated. A guardrail assembly 160 is depicted
which includes a safety apparatus 162 made up of an ET-2000 guardrail
extruder terminal end treatment 164 and an affixed CPSI penetration guard
166. The penetration guard 166 shown is of the type described earlier and
shown in FIGS. 1-5 and 10. However, any other suitable penetration guard
embodiment may be used. In FIG. 15, an automobile 168 is shown approaching
the guardrail assembly 160 in the general direction indicated by arrow 169
so as to result in an end-on impact to the guardrail assembly 160.
Further, the automobile 168 is oriented such that the driver's side door
170 is facing the guardrail assembly 160 and makes a probable point of
impact with the guardrail assembly 160. The driver's side door 170 is
framed on either side by door pillars 170A and 170B.
FIG. 16 illustrates the automobile 168 and the guardrail assembly 160
during the initial portion of the impact between them. As the impact
develops further (in a manner not described in detail herein), the
extruder head will begin to flatten and bend portions of the guardrail.
Further details concerning this aspect of the impact are described in U.S.
Pat. No. 4,928,928, entitled "Guardrail Extruder Terminal," issued to Buth
et al. on May 29, 1990, and U.S. Pat. No. 5,078,366, entitled "Guardrail
Extruder Terminal," issued to Sicking et al. on Jan. 7, 1992 which have
been incorporated herein by reference. As FIG. 16 shows, the penetration
guard 166 is essentially flattened so that it presents an expanded width
area as described previously.
Those skilled in the art will recognize that a CPSI penetration guard might
also be affixed to other fixed roadway objects, such as telephone poles,
lighting poles or breakaway supports to reduce the hazards associated with
impact with them. While the invention has been herein shown and described
in what is presently believed to be the most practical and preferred
embodiment thereof, it will be apparent to those skilled in the art that
many modifications may be made to the invention described while remaining
within the scope of the claims.
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